Let-off mechanism for looms



(No Model.) 4 sheets-sheet 1. A. D. EMERY.

'LET-OFP MEGHANISM FOR LOOMS No. 503,462. Patented Aug. 15, 1893.

' (No Model.) Sheath-sheet 2.,

A. D. EMERY. LET-OPF MEGHANISM 'POR LOOMS.

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LET-OPF MEGHANISM FR LOOMS.

No. 503,462. Patented Aug. 15, 1893.

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IUNITED STATES PATENT OEEIoE.

ABRAM D. EMERY, OF TAUN TON, MASSACHUSETTS.

LET-OFF MECHANISM FOR LOOMS.

SPECIFICATION forming part of Letters Patent No. 503,462, dated August15, 1893.

Application iiled April 25, 1891. Renewed December l, 1892. Serial No.453,689. (No model.)

To @ZZ whom it may concern.-

Be it known that I, ABRAM D. EMERY, of Taunton, Massachusetts, haveinvented certain Improvements in Let-Off Mechanism for Looms, of whichthe following is a specification.

This invention embraces, first, the combination of the whip roller of aloom with a relatively light spring for opposing a prescribed smallresistance to that portion of the rocking movement of the whip rollerinduced by the pull of the warp threads during the formation of thesheds; and a relatively strong spring for opposingincreasing resistanceto the continued rocking movement of the whip roller induced by thegreater pull of the warp threads during the beating up of the weft. TheWarp threads are thus held under modcrate tension except when the beattakes place, during which they are subjected to rapidly The inventionembraces, secondly, a let-off which is automatically regulated in itsoperation by the varying diameter of the warp roll as the weavingoperation proceeds; the organization being such as to aord convenientfacilities for manually setting the let-off to start the loom, andsubsequently adjusting it as may be required to accommodate it tochanged hygrometric conditions of the atmosphere. The varying warptension devices and the self regulating let-off may be independentlyemployed, or they may be associated in the same loom, as illustrated inthe ac companying drawings, which are as follows:

Figure l is an elevation of a portion of the side of a loom forsimultaneously weaving two fabrics side by side, symbolicallyrepresenting a double shed formed of four groups of warp threads fedfrom a single warp roll over a single whip roller, showing the devicesfor administering tension to the warp threads and for automaticallyoperating the let-oitl in the positions which they respectively occupyat the instant when the beat is about to be given. Fig. 2 is a sideelevation similarto Fig. 1, except that it shows the tension and let-offdevices in the positions which they occupy immediately before the beatis given, while the groups of Warp threads are being reversed inposition to form the next double shedding. Fig. 3 is a rear elevation ofthe parts shown in Figs. 1 and 2, Fig. 4 is a horizontal section take-nthrough the plane indicated by the dotted line :c on Fig. 1. Figs. 5 and6 are respectively front and side elevations showing two whip rollersgeared to each other and mounted respectively upon the cross bars of arectangular frame adapted to rock upon a horizontal axis, and havingaffixed to one of its trunnions the radius arm which in Figs. 1 and 2 isrepresented as affixed to the shaft of the single whip roller thereinshown, the object of Figs. 5 and (i` being toillustrate theapplicability of the present improvement in let-od mechanism to thedouble Whip roller system shown and described in Letters Patent of theUnited States, No. 443,612, to A. D. Emery, dated December 30, 1890.

These improvements are applicable to looms in which a single whip rolleris employed, au example of which is shown and described in pendingapplication, Serial No. 367,480, led October 9, 1890; and they are alsoapplicable to looms employing two whip rollers geared together so thatif either whip roller is rocked upon its axis the other whip roller isat the same time necessarily rocked upon its axis in `the oppositedirection, as shown and described in Letters Patent of the United StatesNo. 443,612, to A. D. Emery, dated December 30, 1890. W'hen a singlewhip roller is employed its shaft or trunnion at one end has affixed toit a downwardly dependent radius arm which sways to and fro when thewhip roller rocks, and which constitutes the actuator of the letoffmechanism as shown and described in pending application, Serial No.373,390, filed December 2, 1890. When the double whip roller system isemployed the two whip rollers are mounted respectively upon the twohorizontal members of a rectangular frame provided at its ends withcentral trunnions which afford an axis upon which the whip roller systemrocks without any rocking of the two whip rollers upon their individualaxes. In this case the radius arm which constitutes the actuator of thelet-off mechanism is aiixed to one of the trunnions of therectangularframe. inasmuch as in all cases the swaying movement of thesaid radius arm results from the beating movement of the lay, the saidradius arm may be regarded as being affixed to whatever constitutes themain axis of the Whip IOO Yroller system; it being understood that thesaid main axis is the axis of the Whip roller itself when a single whiproller is employed and is the axis of the rectangular frame upon whichthe whip rollers are mounted when two whip rollers are employed.

Figs. l, 2, 3 and 4 of the drawings represent a portion of the sideframe, a, of a loom in which the warp threads fed from a single warproll, b, to a single whip roller, c, are led over the outer bar, c', andunder the inner bar, c2, of the whip roller to the devices forseparating them into groups and forming such groups into sheds as forexample to the lease rods, d, d", and e, e', by which the warp threadsare separated into the four groups required for weaving side by sidethe. two fabrics @,f. The shaft or trunnion, c3, of the whip' roller hasaffixed to it the downwardly extending radius arm, g, which is providedat the bottom with a lug, g. The lug, g', is transversely perforated toadmit of the extension through it of the pawl setting rod, h, providedwith the preferably adjustable collar, h', for receiving the impact ofthe lug, g', when the swaying movement is imparted to the radius arm, g,by the upward pull upon the warp threads caused from the beat. Thesetting rod, h, is pivotally connected to the radius arm, vl, projectinginwardly from the pawl carrying disk, j, loosely mounted upon the lowerend of the vertical worm spindle, 7c. The pawls, j and 72, are adaptedto engage the ratchet whee17`3, affixed to the worm lo', and looselyturning on the spindle, k. The disk, is-alsoprovided with a radius-arm,5'4, to which is attached one end of the contracting spiral spring, e7'5the opposite end of which is secured to the frame ofthe loom. Thecontracting force of the spring, j5, thrusts the setting rod, h, forwardand keeps the free end, h2, of the setting rod against the face of theinvolute cam, l, provided with the concentrically curved flange, Z', towhich is adjustably fastened one end of the strap, m. The opposite endof the strap m, is secured to a crank arm, m', affixed to a rock shaft,m2,5 to which is also affixed the governorlever ,m3, the free end ofwhich bears upon and is supported by the surface of the roll of warp,and is consequently permitted to fall as thewarp roll graduallydiminishes in diameter during the continuance of the weaving operation.The falling of the actuating arm, m3, and the consequent rocking of thecrank arm, m', slacks the strap,m, and permits the involute cam, Z, torock upon its axis in obedience to the force of gravity. Such rockingoftheinvolutecam,l,di i

automatically produced increase in the ranges of movement imparted tothe setting rod h, as the warp roll gradually diminishes in diameter.The worm, 7c', affixed to the ratchet wheel, j, and loosely mounted uponthe worm spindle, k, engages the worm wheel, k2 affixed to thecountershaft, kto which there is also affixed the pinion, 7a4, whichmeshes with the teeth of the cog-wheel, 765, affixed to the shaft of thewarp roll, b. Owing to the described gradual increase in the range ofmotion of the setting bar, h, there is a corresponding increase in theextent of rotation imparted to the warp roll, the ratio of which isinversely proportional to diminution of the warp roll in diameter, sothat the warp threads are delivered from the warp roll at a uniformrate. In the let-off mechanism described in the hereinbefore mentionedpending application, Serial No. 373,390, manually adjustable devices areemployed for regulating the delivery of the warp. In the present casenot only is the let-off governed automatically, but the governingmechanism affords peculiarly convenient facilities for setting thelet-off when the loom is to be started, and for altering the let-offwhenever changed hygrometric conditions or other causes may render suchalterations desirable. Such alterations are effected by loosening theclamp, m6, so as to loosen the strap, m, and by then turning thegovernor cam in one direction or the other, as may be required, andagain clamping the strap to the concentric segment, Z. This amounts tothe same thing as either lengthening or shortening the strap, fm., andhas the effect of either increasing or diminishing the range of movementimparted to the setting rod, h, by the inward sway of the radius arm, g,at the time of the beat. Y

The devices for administering the varying` tension to the warp threadsembrace first the primary expanding spiral spring, n, abutting at itsrear end against the fixed standard, d', and surrounding the rod, n',and abutting at its forwardend against the recessed nut, n2, screwed onto the rod, n. tion of the rod, in', is turned down to form the stem,n3, and present an annular shoulder, n4, for bearing against theadjacent end of a lug, ns, projecting from the radins arm g. The lug,m5, is perforated to admit of the extension through it of the stem,n3.The expanding spring, n, is proportioned with reference to making theforce of its thrust against the radius arm, g, sufficient to rock theinner bar or bars of the whip-roller or whip-rollers downward andadminister a moderate tension to the wa rp threads during the intervalsbetween the beats, the said spring n exerting a moderate force upon thewhip roller in opposition to the force exerted thereon by the warpthreads during the formation of the sheds. When the beat takes place theupward pull of the warp threads causes the radius arm, g, to swaybackward and to further compress the expanding spring, n. At thecommence- The forward porment of the beat, the radius arm, f, hasacquired substantially the position in which it is represented in Fig.l, and its farther backward movement is then resisted by the secondaryexpanding spiral spring, o, abutting at its rear end against thestandard, a', and surrounding the rod, o, and abutting at its forwardend against the recessed nut, 02, screwed onto the rod, o. The forwardend of the rod, o, is screw threaded and has screwed on to it the twonuts, o3 and 04, the latter of which acts as a jam nut to hold the nut,oa, in the position to which it may have been adjusted with reference tohaving it bear at the proper time against the end of the lug, o5,projecting from the face of the radius arm, g. rlhe lug, 05, isperforated to allow the extension through it of the forward end, o6, ofthe rod, o. The rear end, o7, of the rod, o', eX- tends through anaperture in the standard, a', and is provided with the jam nuts, o8 ando". It will be seen that by altering the position of the jam nuts, o8and o9,the tension of the secondary spring may be varied at will, andthat altering the position of the jam nuts, o3 and o4, alters the stagein the backward swaying movement of the radius arm, g, at which itcommences to encounter the resistance of the secondary spring.

It has heretofore been proposed to use a weight for giving added tensionto the warp threads at the instant of the beat; but the employment ofthespring for this purpose, as herein shown, is not only advantageousbecause of the greater facility and convenience with which the springmay be applied, but because the spring performs functions which theweight is incapable of. Thus the spring, o, opposes an increasingresistance to the backward sway of the radius arm, g. A weight requiresto be moved in a direction opposite to the direction of the force whichgravity exerts upon it, and hence in a quick running loom a weight,after having been lifted, will not fall with the necessary quickness.There is not time enough after one beat for the momentum of the upwardlymoving weight to be overcome by gravity and for the weight to fall backto its normal position before the next beat occurs. On the contrary, thespring, o, when compressed by the backward sway of the radius arm, g,exerts its resilient force continuously and hence instantaneouslythrusts the radius arm, g, forward at the conclusion of the beat.Therefore, however rapidly the loom runs, the tension-exertin g devicesherein shown are always in action and in readiness to perform theirfunctions at every beat.

Figs. 5 and 6 of the drawings illustrate the manner of applying thepresent improvements in a loom employing two whip-rollers, p and 1J',geared to each other and mounted in the cross bars of a rectangularframe, p2, provided with trunnions, p3, which constitute the main axisof the whip-roller system. Fig. 5 shows one of the trunnions, p,projecting through its bearing in the frame, A, of the loom, and havingrigidly mounted upon it the hollow hub of the radius arm, g. Fig. 6illustrates a form of shedding in connection with which two whip-rollersare employed. The effect of the beat is to pull upward the innerbars ofboth whip-rollers,p and p and to thus cause the rectangular frame, p2,to rock upon its axis, p3, and to sway the radius arm, g, in a rearwarddirection and thereby give motion to the setting rod, h, of the let-offgear.

As will be obvious, the radius arm, g, performs the same functions withrelation to the double whip roller system as those which it performswith relation to the single whiproller; hence the trunnion, c3, of thesingle whip roller and the trunnion, p3, of the rectangular fraine inwhich the two whip-rollers are mounted are, for the purposes of thepresent invention, to be regarded as equivalents and as constituting ineither case the main axis of the whip-roller system.

What is claimed as the invention is-- l. The combination of the whiproller system of a loom with a primary spring adj usted to exert amoderate force upon said whip roller system in opposition to the forceexerted thereon by the warp threads during the formation of the sheds,and a secondary spring adjusted to exert an additional and increasingforce upon said whip roller system in opposition to the force exertedthereon during the beat.

2. The combination, as herein described, of the radius arm g, aiiixed tothe main axis of the whip roller system of a loom, the spring n andconnections between the same and the whip roller system, the rod o', thenut o3 adj ustable on said rod for regulating its operative length andthe secondary spring o for operating upon said rod only at the instantof the beat, substantially as described.

3. In a loom for weaving, the combination of let-off gearing, means foroperating said gearing, a regulator cam for varying the range ofoperation of said means for operating said gearing, a governor leveradapted to bear upon and be supported by the surface of the roll ofwarp, and connections between the govorner-lever and cam, consisting ofthe rockshaft m2, crank-arm m mounted on said shaft, strap m connectingsaid arm and cam, and adj usting-clamp mG for coupling the strap andcam, whereby the governor-lever not only controls the movement of thecam and the let-off as the warp roll diminishes in diameter, butprovision is made for conveniently adjusting the let-off to compensatefor varying conditions of the warp threads due to atmospheric changes orother causes.

4f. The combination of a warp-roll, a gov ernor-lever adapted to bearupon and be supported by the surface of the roll of warp, a regulator'cam, and suitable adjustable connections between the governor-lever andthe regulator cam, substantially as and for the purposes set forth.

5. The combination of a warp rol1,a gov- IIO ernor-lever adapted to bearupon and be supported by the surface of the roll 0f Warp, thesetting-bar h, the radius arm g, connected directly to the Whip rollersystem, the regula.- tor cam and adjustable connections between thegovernor and the cam, substantially as described and for the purposesset forth.

6. The combination of a Warp roll, the governor-lever ma, adapted tobear upon and be supported by the surface of the Warp 1011, the 1o rockshaft, m2, the crank arm m', the strap, m, the invoiute cam, Z, andtheclampmt, for adjustably connecting the cam, Z, to the strap, fm, as andfor the purposes set forth.

ABRAM D. EMERY. Witnesses:

H. J. FULLER, A. M. JONES.

